The objective of this proposal is to further our understanding of weaning, the transition from social and nutritional dependence on the mother to greater behavioral independence, a transition common to all altricial mammals. This will be achieved through the observation of (1) social and ingestive development in albino rats, (2) changing maternal behavior during pup ontogeny and (3) the interactions between developing pups and their mothers, and other adult rats. The analysis will employ time-elapse video photography to sample behavior in a semi-natural environment for 24 hour, at 5-10 day intervals. This record will be reviewed and transcribed to determine the approximate frequency, duration and sequential ordering of social and ingestive behaviors. Specifically, I plan to focus on the pups' experiences during weaning and document the changing interactions with the mother which culminate in the cessaton of suckling. I will examine how the dam contiues to influence the pups' food selection following weaning, and how she contributes to their avoidance of predators. The behavior of mothers rearing pups in isolation will be compared with that of mothers rearing young in a community. I will also observe how other members of the rat community contribute to the socialization of the weanlings, and how the weanlings interact with the community at large.